Relational Instance-Based Learning with Lists and Terms

The similarity measures used in first-order IBL so far have been limited to the function-free case. In this paper we show that a lot of power can be gained by allowing lists and other terms in the input representation and designing similarity measures that work directly on these structures. We present an improved similarity measure for the first-order instance-based learner ribl that employs the concept of edit distances to efficiently compute distances between lists and terms, discuss its computational and formal properties, and empirically demonstrate its additional power on a problem from the domain of biochemistry. The paper also includes a thorough reconstruction of ribl's overall algorithm.     

复杂结构归纳学习研究

复杂结构归纳学习的需求近年来快速增长。复杂结构归纳学习方法按照知识表示方式不同分为基于逻辑的方法与基于数学图的方法。阐述了复杂结构归纳学习研究的历史沿革,介绍、分析和对比了不同知识表示方式下的学习方法,给出了复杂结构归纳学习将来发展面临的挑战和需重点解决的问题。     

用于图分类的组合维核方法

对图等内含结构信息的数据进行学习,是机器学习领域的一个重要问题.核方法是解决此类问题的一种有效技术.文中针对分子图分类问题,基于Swamidass等人的工作,提出用于图分类的组合维核方法.该方法首先构建融合一维信息的二维核来刻画分子化学特征,然后基于分子力学的相关知识,利用几何信息构建三维核来刻画分子物理性质.在此基础上对不同维度的核进行集成,通过求解二次约束二次规划问题来获得最优核组合.实验结果表明,文中方法比现有技术具有更好的性能.     

Separate-and-Conquer Rule Learning

This paper is a survey of inductive rule learning algorithms that use a separate-and-conquer strategy. This strategy can be traced back to the AQ learning system and still enjoys popularity as can be seen from its frequent use in inductive logic programming systems. We will put this wide variety of algorithms into a single framework and analyze them along three different dimensions, namely their search, language and overfitting avoidance biases.     

结构化数据在电力年金体系中的应用

大多数电力系统都存有年金托管机构的基本信息,但目前由于托管机构的投资的实效性和市场的约束性导致各投资机构的投资信息独立,且投资信息的保密程度过高,往往只能通过内网邮件的形式交互,使得年金专责无法在短时间内对托管机构的投资方向和投资利润做对比,以至于无法比较托管机构的优劣。在邮件信息中往往存在大量的且关键的信息,基于对结构化数据的模糊识别与算法,并根据定价日、科目名称、成本、市值建立数据模型,实现重要信息的分类处理,解决了投资信息的实时录入和对托管机构营收的准确判断。     

Extracting Web Data Using Instance-Based Learning

This paper studies structured data extraction from Web pages. Existing approaches to data extraction include wrapper induction and automated methods. In this paper, we propose an instance-based learning method, which performs extraction by comparing each new instance to be extracted with labeled instances. The key advantage of our method is that it does not require an initial set of labeled pages to learn extraction rules as in wrapper induction. Instead, the algorithm is able to start extraction from a single labeled instance. Only when a new instance cannot be extracted does it need labeling. This avoids unnecessary page labeling, which solves a major problem with inductive learning (or wrapper induction), i.e., the set of labeled instances may not be representative of all other instances. The instance-based approach is very natural because structured data on the Web usually follow some fixed templates. Pages of the same template usually can be extracted based on a single page instance of the template. A novel technique is proposed to match a new instance with a manually labeled instance and in the process to extract the required data items from the new instance. The technique is also very efficient. Experimental results based on 1,200 pages from 24 diverse Web sites demonstrate the effectiveness of the method. It also outperforms the state-of-the-art existing systems significantly.     

Confirmation-Guided Discovery of First-Order Rules with Tertius

This paper deals with learning first-order logic rules from data lacking an explicit classification predicate. Consequently, the learned rules are not restricted to predicate definitions as in supervised inductive logic programming. First-order logic offers the ability to deal with structured, multi-relational knowledge. Possible applications include first-order knowledge discovery, induction of integrity constraints in databases, multiple predicate learning, and learning mixed theories of predicate definitions and integrity constraints. One of the contributions of our work is a heuristic measure of confirmation, trading off novelty and satisfaction of the rule. The approach has been implemented in the Tertius system. The system performs an optimal best-first search, finding the k most confirmed hypotheses, and includes a non-redundant refinement operator to avoid duplicates in the search. Tertius can be adapted to many different domains by tuning its parameters, and it can deal either with individual-based representations by upgrading propositional representations to first-order, or with general logical rules. We describe a number of experiments demonstrating the feasibility and flexibility of our approach.     

一种用于工作流的结构化数据模型及应用研究

为了实现工作流中数据信息的层次化表达和管理,本文提出了一种结构化数据模型(SDM)。该模型通过文档信息表(DIF)将工作流的数据信息组织成串行、并行、条件和循环四种可递归定义的数据类型,给出了这些数据类型的数学定义,用树组织和描述文档信息表。本文还研究了通过SDM直接生成复合表单的方法。这种复合表单不仅包含了需要处理的属性数据,还包含了各属性之间的层次关系,使终端用户使用起来直观易懂。